1. Field of the Invention
The present invention concerns an optical pickup apparatus for an optical disk apparatus improved in order to build in a personal computer (“PC” hereinafter), especially in a notebook PC.
2. Detailed Description of the Prior Art
In general, a PC is equipped as standard with an optical disk apparatus for reproducing record of or recording information in an optical disk abbreviated to CD (compact disk), DVD (digital versatile disk), which is essential for processing information powerfully and at the same time required to present a high accuracy and reliability according to the increase of storage density and the increase of readout speed, writing speed or others.
FIG. 9 shows an optical pickup apparatus for an optical disk apparatus adopted relatively largely for a desk top PC, and the same apparatus is so composed that, a light beam emitted from an semiconductor laser device 101 transmits a beam splitter 102 and enters an objective lens 104 installed in a lens holder 103. Then, this objective lens 104 collects the light beam and spots of beam are formed in fine pits formed on a recording surface of an optical disk D.
The beam reflected from the recording surface of the optical disk D returns transmitting the objective lens 104 and is reflected in a right angle direction by the beam splitter 102. Then, the light beam intensity detected by a photodiode 105 enables to read the record bits on the optical disk D.
By the way, as face run-out or eccentricity exist, for a rapidly rotating optical disk D, it is composed to irradiated the recording bit of the optical disk D with a spot of the beam correctly all the times, by making the objective lens 104 follow, in respect to this face run-out or eccentricity, by an objective lens driving apparatus.
This objective lens driving apparatus is the one where a focus coil 106 is wound on a side face of the lens holder 103 for holding the objective lens 104, and further tracking coils 107 are disposed by one pair respectively on the opposite two faces. Then, a permanent magnet 108 and a yoke base 109 are arranged in a way to pinch these focus coils 106 and the tracking coil 107, and compose a magnetic circuit. The lens holder 103 is supported by a suspension wire 110 and a suspension holder 111, and the whole lens holder 103 is driven by a control current supplied to the focus coil 106 and the tracking coil 107, so that the objective lens 104 can be positioned correctly.
Next, an optical pickup apparatus shown in FIG. 10 has been developed for an optical disk apparatus to be built in a notebook PC and respective components are composed extremely flat, in order to integrate in a flat body of the notebook PC. In the same drawing, the symbol 112 is a lens holder, holding an objective lens 113 at the front end and a focus coil 114 at the rear end. Two tracking coils 115 are affixed to an open end face of the focus coil, and the focus coil 114 and the tracking coil 115 are supported by a suspension wire 118 and a suspension holder 119 so that they are positioned simultaneously in a magnetic circuit formed by permanent magnets 116, 117. Then it is so composed that light beam incident transversely into a rising mirror 121 arranged in a frame body (not shown) under a yoke base 120 be incident to the objective lens 113.